Technology growth cycles move quickly and the UAV industry is not immune to it. The growth over the last year in the United States and across the world is opening up applications to a large, varied usage base with more coming all the time.
Part of this is fueled by growth by loosened regulations (e.g. FAA), others have been from a open purse for funding of many different ventures which goes beyond the UAV market. TechCrunch put out a recent article that the technology market is nearing another funding bubble like one around 15 years ago. This means a coming shakedown for viable ventures in the greater technology world along with the sub-market of UAVs.
In basic Market Strategy literature, the Product Life Cycle talks about the basic phases of product development from introduction to retirement. You can read about it here. Late in 2014 the market moved from the Introduction phases to the Growth phase and with the technology funding bubble and so many possible applications, a market transition to the Maturity phases is coming as the viability of many applications will be put to the test. As funding is expected to slow down, the applications of UAVs will have to be viable to continue to evolve in the future. Some will be related to traditional remote sensing/aerial survey, some will be for unrelated flight activities.